U.S. patent number 4,886,432 [Application Number 07/210,332] was granted by the patent office on 1989-12-12 for bladder pump assembly.
This patent grant is currently assigned to Engineering Enterprises, Inc.. Invention is credited to Denver K. Kimberlin.
United States Patent |
4,886,432 |
Kimberlin |
December 12, 1989 |
Bladder pump assembly
Abstract
A downhole bladder pump for pumping ligher-than-water liquids.
The pump includes an outer tube closed at its bottom and top, but
having slots adjacent its upper end to admit the liquid to be
pumped. Positioned concentrically within the outer tube is a
cylindrical bladder chamber. A cylindrical bladder is mounted
within the bladder chamber and registers with the internal surface
of such chamber. A cyclically-operated pneumatic control system
periodically delivers pressurized air to the space between the
bladder and the bladder chamber to collapse the bladder and pump
liquid which has flowed into the bladder. At other times during the
cycle, the control system draws the bladder outwardly against the
internal surface of the bladder housing by the application of
vacuum. The liquid to be pumped is then forced into the bladder
through a check valve subassembly positioned in the lower end of
the bladder housing. This liquid is next expressed or discharged
through an upper check valve system located in the upper end of the
bladder housing.
Inventors: |
Kimberlin; Denver K. (Norman,
OK) |
Assignee: |
Engineering Enterprises, Inc.
(Norman, OK)
|
Family
ID: |
22782488 |
Appl.
No.: |
07/210,332 |
Filed: |
June 23, 1988 |
Current U.S.
Class: |
417/478; 91/237;
91/240; 91/250; 92/90 |
Current CPC
Class: |
F04B
43/10 (20130101); F04B 47/08 (20130101) |
Current International
Class: |
F04B
47/08 (20060101); F04B 47/00 (20060101); F04B
43/10 (20060101); F04B 43/00 (20060101); F04B
043/08 () |
Field of
Search: |
;417/390,395,378,379,394,401,403,404,413,478 ;138/30
;166/105.1,265,269 ;210/416.1,525,776 ;92/89,90,91,92 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Pulse Pump Pneumatic Pumping System by QED Environmental Systems,
Inc. .
Teflon Bladder Pump and Controller Manual, Modes Industrial
Plastics, the Duriron Company, Inc..
|
Primary Examiner: Croyle; Carlton R.
Assistant Examiner: Blackman; Robert N.
Attorney, Agent or Firm: Laney, Dougherty, Hessin &
Beavers
Claims
What is claimed is:
1. A bladder pump assembly comprising:
an external skimmer tube having a closed bottom, and a closed upper
end;
means for admitting liquid to the interior of the skimmer tube from
a location near the upper end thereof;
a cylindrical bladder support chamber positioned concentrically
within the external skimmer tube, and defining an annular space
therewith, said bladder support chamber having a lower end spaced
upwardly from the closed bottom of said skimmer tube and having an
upper end, said bladder support chamber comprising a pair of
semicylindrical members each having a pair of opposed, radially
outwardly extending diametric flanges with the flanges on the
semicylindrical members in said pair of said semicylindrical
members abutting each other and secured together;
a flexible bladder lining the inner wall of at least a major
portion of said support chamber and capable of flexing radially
inwardly from said inner wall toward the axis of said cylindrical
bladder support chamber;
a lower check valve assembly pressed into the lower end of the
bladder support chamber and having the lower end of said bladder
therearound and trapped between the exterior of said lower check
valve assembly and the inner wall of said bladder support chamber,
said lower check valve assembly functioning to open to admit liquid
into said bladder from said annular space and said space between
said support chamber lower end and said skimmer tube lower end when
no pressure is applied to the outer side of said cylindrical
flexible chamber;
an upper check valve assembly pressed into the upper end of the
bladder support chamber and having the upper end of said bladder
therearound and trapped between said upper check valve assembly and
the inner wall of said bladder support chamber, said upper check
valve assembly functioning to open to permit the discharge of
liquid therethrough from the interior of said bladder when air
under pressure is introduced between said bladder and said bladder
support chamber;
a liquid discharge pipe connected to said upper check valve
assembly for receiving liquid pumped through said upper check valve
assembly from the interior of the bladder; and
a remote pneumatic pump cycle control system connected to the
bladder support chamber for delivering air under pressure to the
space between said bladder and said bladder support chamber, and
for evacuating the space between the bladder and the bladder
support chamber following the radially inward collapse of the
bladder by air under pressure.
2. A bladder pump assembly as defined in claim 1 wherein pump cycle
control system comprises:
a source of air under pressure;
a source of vacuum; and
a three-way control valve connected to said bladder support chamber
for periodically shifting between (a) a pressuring position for
delivering air under pressure from said source of air under
pressure to the space between said bladder and said bladder support
chamber, and (b) an evacuating position for connecting said space
between said bladder and said bladder support chamber to said
source of vacuum, and (c) an atmsopheric exhaust position in which
air from said space between the bladder and said bladder support
chamber is vented to the atmosphere.
3. A bladder pump assembly as defined in claim 2 wherein said
source of vacuum is a Venturi ejector.
4. A bladder pump assembly comprising:
an external skimmer tube having a closed bottom, and a closed upper
end;
means for admitting liquid to the interior of the skimmer tube from
a location near the upper end thereof;
a cylindrical bladder support chamber positioned concentrically
within the external skimmer tube and defining an annular space
therewith, said bladder support chamber having a lower end spaced
upwardly from the closed bottom of said skimmer tube and having an
upper end;
a flexible bladder lining the inner wall of at least a major
portion of said support chamber and capable of flexing radially
inwardly from said inner wall toward the axis of said cylindrical
bladder support chamber;
a lower check valve assembly pressed into the lower end of the
bladder support chamber and having the lower end of said bladder
therearound and trapped between the exterior of said lower check
valve assembly and the inner wall of said bladder support chamber,
said lower check valve assembly functioning to open to admit liquid
into said bladder from said annular space and said space between
said support chamber lower end and said skimmer tube lower end when
no pressure is applied to the outer side of said flexible
bladder;
an upper check valve assembly pressed into the upper end of the
bladder support chamber and having the upper end of said bladder
therearound and trapped between said upper check valve assembly and
the inner wall of said bladder support chamber, said upper check
valve assembly functioning to open to permit the discharge of
liquid therethrough from the interior of said bladder when air
under pressure is introduced between said bladder and said bladder
support chamber;
a liquid discharge pipe connected to said upper check valve
assembly for receiving liquid pumped through said upper check valve
assembly from the interior of the bladder; and
a remote pneumatic pump cycle control system connected to the
bladder support chamber for delivering air under pressure to the
space between said bladder and said bladder support chamber, and
for evacuating the space between the bladder and the bladder
support chamber following the radially inward collapse of the
bladder by air under pressure, said pump cycle control system
comprising:
a source of air under pressure;
a source of vacuum; and
a three-way control valve connected to said bladder support chamber
for periodically shifting between (a) a pressuring position for
delivering air under pressure from said source of air under
pressure to the space between said bladder and said bladder support
chamber, and (b) an evacuating position for connecting said space
between said bladder and said bladder support chamber to said
source of vacuum, and (c) an atmospheric exhaust position in which
air from said space between the bladder and said bladder support
chamber is vented to the atmosphere, said pump cycle control system
further comprising:
a pilot included in said three-way control valve for shifting the
control valve in response to air pressure applied to the pilot;
a three-way exhaust cycle valve;
a three-way vacuum cycle valve;
a three-way pressure cycle valve; and
conduit means interconnecting said exhaust cycle valve, said vacuum
cycle valve and said pressure cycle valve and the pilot of said
three-way control valve.
5. A bladder pump assembly as defined in claim 4 wherein said
cylindrical bladder support chamber comprises a pair of
semicylindrical members each having a pair of opposed radially
outwardly extending diametric flanges, with the flange pairs of
said semicylindrical members abutting each other and secured
together.
6. A bladder pump assembly for pumping deleterious low density
liquids from a subterranean location comprising:
an external skimmer tube having a fluid intake slotted upper end
portion, and a closed lower end;
a bladder support chamber having an internal wall and a lower end,
the bladder support chamber positioned within the external skimmer
tube and defining an annular space therebetween, the lower end of
the bladder support chamber terminating a distance from the closed
lower end of the external skimmer tube;
a flexible bladder supported within the bladder support chamber,
the flexible bladder having an upper end, a lower end and a length
substantially coextensive in length with the bladder support
chamber, the flexible bladder selectively movable between an
expanded first position and a collapsed second position, in the
expanded first position the flexible bladder being disposed along
the internal wall of the bladder support chamber, in the collapsed
second position the flexible bladder being flexed radially inwardly
from the inner wall of the bladder support chamber in the direction
of the axis of the cylindrical bladder support chamber;
a lower check valve supported by the lower end of the flexible
bladder and extending into the cavity formed between the lower end
of the bladder support chamber and the lower end of the external
skimmer tube, the lower check valve having an open mode and a
closed mode, in the open mode of the lower check valve the flexible
bladder being disposed in the first position so that fluid can be
introduced into the flexible bladder, in the closed mode of the
lower check valve the flexible bladder being either in transition
toward the second collapsed position, or at the second collapsed
position;
an upper check valve disposed in the upper end of the flexible
bladder, the upper check valve having an open mode and a closed
mode, in the open mode of the upper check valve the flexible
bladder being disposed in the collapsed second position so that
fluid can be removed from the flexible blader, and in the closed
mode of the upper check valve the flexible bladder being either in
transition toward the first position, or at the first position;
means operably connected to the cylindrical bladder support chamber
for selectively delivering fluid under pressure to the bladder
support chamber and thereby moving the flexible bladder to the
second collapsed position, and for evacuating the bladder support
chamber so that the flexible bladder can be moved to the first
expanded position, said means for selectively delivering fluid
under pressure to the bladder support chamber and for evacuating
the same comprising:
at least one flow tube disposed within the annular space formed
between the external skimmer tube and the bladder support chamber,
one end of the flow tube openly communicating with the interior
portion of the bladder support chamber;
pneumatic pump cycle control means operably connected to the flow
tube for delivering air under pressure through the flow tube to the
bladder support chamber and for evacuating the bladder support
chamber; and
automatic timing and control means for controlling the time periods
during the pumping cycles of the pneumatic pump cycle control
system to evacuate the bladder support chamber so that the bladder
can be filled with the liquid, and to charge the bladder support
chamber when fluid is expelled from the bladder; and
wherein each of said lower and upper check valves comprises:
a check valve head having a substantially cylindrical upper portion
and a frustoconical lower portion, the frustoconical lower portion
positionable within and adjacent the end of the bladder, the check
valve head having a central, axially extending bore extending
therethrough, the portion of the bore adjacent the frustoconical
lower portion being provided with threads, said check valve head
having an external annular groove adapted to receive a sealing
member;
a check valve seat having external threads adapted to matingly
engage the threaded portion of the bore extending through the head,
the check valve seat having a seat surface and a fluid passageway
extending therethrough, the check valve seat further characterized
as having transverse ports for permitting fluid to enter the
passageway thereof;
a ball check; and
a ball check stop rod extending diametrically across the bore in
the cylindrical upper portion for restricting the opening movement
of the ball check as the same is removed from the seat surface when
the check valve is in an open mode.
7. A bladder pump assembly as defined in claim 6 wherein the
bladder support chamber comprises:
a pair of semicylindrical members each having a pair of radially
outwardly extending diametric flanges with the flange pairs of the
semicylindrical members abutting each other; and
means for connecting the abutting flanges of the semicylindrical
members; and
wherein the bladder comprises:
a pair of opposed flexible members each having a pair of opposed
outwardly extending diametric flanges at opposite sides thereof
with the flange pairs of the opposed flexible members abutting
flanges of the semicylindrical members of the bladder support
chamber.
8. A bladder pump assembly comprising:
an external tube having a closed end and fluid inlet means formed
in an upper end portion thereof for permitting liquid located
adjacent the fluid inlet means to enter the external tube;
a bladder chamber positioned within the external tube so as to
define a space therebetween for receiving the liquid entering the
external tube, one end of the bladder chamber terminating a
distance from the closed lower end of the external tube such that a
cavity is formed therebetween;
a flexible bladder supported within the bladder chamber and having
an upper end, a lower end and a length substantially coextensive in
length with the bladder chamber;
valve means for permitting liquid to be alternately introduced into
the bladder and expelled therefrom while preventing reverse flow of
liquid from the bladder into the cavity when liquid is expelled,
said valve means comprising:
a lower check valve assembly disposed in the lower end of the
bladder chamber, the lower check valve assembly having an open mode
and a closed mode, and in the open mode of the lower check valve
assembly the flexible bladder being disposed in an expanded first
position so that fluid can be introduced into the flexible bladder,
and in the closed mode of the lower check valve assembly, the
flexible bladder being in the second, collapsed position;
an upper check valve assembly disposed in the upper end of the
flexible bladder, the upper check valve assembly having an open
mode and a closed mode, and in the open mode of said upper check
valve assembly, said flexible bladder being disposed in said
collapsed second position so that fluid can be removed from the
flexible bladder, and in the closed mode of said upper check valve
assembly, the flexible bladder being in the expanded first
position; and
means operably connected to the cylindrical bladder support chamber
for selectively delivering fluid under pressure to the bladder
support chamber, and thereby moving the flexible bladder to the
second, collapsed position, and for evacuating the bladder support
chamber so that the flexible bladder can be moved to the expanded
first position, said means operably connected to the cylindrical
bladder support chamber comprising:
at least one flow tube disposed within the annular space formed
between the external skimmer tube and the bladder support chamber
and having one end thereof openly communicating with the interior
portion of the bladder support chamber for delivering fluid between
the chamber and said flexible bladder;
a pneumatic pump cycle control system operably connected to said
flow tube for delivering air under pressure through the flow tube
to the bladder support chamber, and for evacuating the bladder
support chamber; and
automatic timing and control means for controlling the time periods
during the pumping cycle of the pneumatic pump cycle control system
to evacuate the bladder support chamber so that the bladder can be
filled with the liquid, and to charge the bladder support chamber
when fluid is expelled from the bladder; and
a liquid discharge conduit connected to the upper check valve
assembly for receiving liquid pumped through the upper check valve
assembly from the interior of the bladder and delivering such
received liquid to a remote location.
9. A bladder pump assembly comprising:
an external skimmer tube having a closed bottom, and an upper
end;
means for admitting liquid to the interior of the skimmer tube from
a location near the upper end thereof;
a cylindrical bladder support chamber positioned concentrically
within the external skimmer tube, and defining an annular space
therewith, said bladder support chamber having a lower end spaced
upwardly from the closed bottom of said skimmer tube and having an
upper end;
a flexible, two-part bladder positioned within said cylindrical
support chamber, said two-part bladder comprising a pair of
superimposed sheets of flexible material having opposite side edges
secured together to form a fluid tight enclosure between said
sheets, said flexible bladder being positioned relatively near to
the inner wall of at least a major portion of said support chamber
at one time during the operation of said bladder pump as compared
to the bladder's position at a different time during the operation
of the bladder pump, and capable of flexing radially inwardly from
its position relatively near to said inner wall toward the axis of
said cylindrical support chamber;
a lower check valve assembly pressed into the lower end of the
bladder support chamber and having the lower end of said bladder
positioned therearound and sealed therearound so that said lower
check valve assembly communicates with the interior of said bladder
said lower check valve assembly functioning to open to admit liquid
into said bladder from said annular space, and from said space
between said support chamber lower end and said skimmer tube lower
end when no pressure is applied to the outer side of said flexible
chamber;
an upper check valve assembly pressed into the upper end of the
bladder support chamber and having the upper end of said bladder
extending therearound and sealed therearound, and said upper check
valve assembly communicating with the interior of the bladder, said
upper check valve assembly functioning to open to permit the
discharge of liquid therethrough from the interior of said bladder
when air under pressure is introduced between said bladder and said
bladder support chamber;
a liquid discharge pipe connected to said upper check valve
assembly for receiving liquid pumped through said upper check valve
assembly from the interior of the bladder; and
a remote pneumatic pump cycle control system connected to the
bladder support chamber for delivering air under pressure to the
space between said bladder and said bladder support chamber, and
for evacuating the space between the bladder and the bladder
support chamber following the radially inward collapse of the
bladder by air under pressure.
Description
FIELD OF THE INVENTION
This invention relates to a gas powered bladder pump assembly
useful for pumping deleterious low density liquids from a
subterranean location without comtamination of the air or other gas
used to operate the pump.
BACKGROUND OF THE INVENTION
Brief Description of the Prior Art
The need for a pump capable of pumping supernatant, relatively low
density, contaminant liquids from a subterranean environment in
which such liquids overlie and float upon the water in a water
saturated formation has recently substantially intensified. The
greater emphasis on the separation from, and removal of, such
liquids from ground waters has resulted in part from an enhanced
sensitivity of society to the problem of maintaining fresh water
supplies in an uncontaminated condition.
One category of environmental comtaminant being encountered with
increasing frequency includes liquids which are insoluble in, and
substantially immiscible with, water, whether fresh or saline, and
which, in having a density which is different from that of water,
either float on the surface of the water, or are located beneath
the water by reason of being more dense than water. It is now
known, for example, that adjacent to some oil and gas refineries
which have operated over a period of many years, the accumulation
of hydrocarbons which have leaked from tanks and pipelines in the
refinery has, in some instances, constituted a serious source of
contamination of aquifers and other subterranean waters. Further,
the quantities of such hydrocarbons which stratify on the surface
of subterranean waters have sometimes been sufficient to make their
recovery an economically attractive proposition.
For the purpose of recovering hydrocarbons, or other
lighter-than-water liquids from a subterranean environment where
these liquids float on the ground water present, several types of
specializied pumps which are well adapted to recover these liquids
by pumping, following their separation from the water, have been
developed.
In general, the hydrocarbons or other low density liquids are
separated from water upon which such liquids float by a density
difference and gravity flow technique in which the pump to be
utilized is first lowered to a position in which an intake of the
pump is located at approximately the location of the interface
between the water and the supernatant hydrocarbon. Openings to the
pump housing are provided at a level above this interface so that
only hydrocarbons will flow through the openings and into the pump
for purposes of removal by the pump. After a pumping chamber within
the pump has been filled with the liquid which enters in the
described fashion, one type of pump in use is pneumatically
actuated to express or drive the liquid thus accumulated in the
pump upwardly to the surface where it can be recovered at a
suitable remote location. The air or other gas used to operate the
pump is cyclically charged under pressure, and, alternately, is
exhausted to the atmosphere during a different phase of the pump
operation.
Patents which disclose pumps of the type described which are
pneumatically operated to remove separated hydrocarbons by
alternately charging air under pressure to the pump, and then
venting air in the pump chamber to the atmosphere as the chamber is
filled with hydrocarbon liquid, include U.S. Pat. No. 4,678,040 to
McLaughlin et al, U.S. Pat. No. 4,546,830 to McLaughlin et al, U.S.
Pat. No. 4,527,633 to McLaughlin et al, U.S. Pat. No. 129,353 to
Lytle, U.S. Pat. No. 751,323 to Moran et al, U.S. Pat. No. 801,991
to Gosse, U.S. Pat. No. 2,171,402 to Muir, U.S. Pat. No. 3,894,583
to Morgan, U.S. Pat. No. 3,991,825 to Morgan and U.S. Pat. No.
4,025,237 to French.
The commercially available Pulse Pump of QED Environmental Systems,
Inc., is a pneumatically controlled pump useful for the described
purpose.
A pump utilizing a Teflon (polytetrafluoroethylene) bladder to
intake, and then discharge, a water sample is marketed by the MIP
Division of The Durison Company, Inc. of Dayton, Ohio. In this
pump, the liquid to be pumped flows through a check valve into a
space between the exterior of the bladder and a rigid pump housing.
This causes the bladder to collapse. Air is then forced into the
bladder under pressure to expel the accumulated liquid from the
space between the bladder and the rigid housing.
BRIEF DESCRIPTION OF THE PRESENT INVENTION
The present invention is a bladder pump useful for pumping
hydrocarbons (or other lighter-than-water liquids) from a
subterranean location so as to effect a separation of the
hydrocarbons from ground water. The bladder pump functions
effectively to pump hydrocarbons or other pollutant low density
liquids without contaimination of the air, or other pumping gas
used to operate the pump and recirculated to a location above the
ground during the operation of the pump.
Broadly described, the bladder pump of the invention comprises an
external cylindrical skimmer tube which is closed at its opposite
ends by suitable closure plates or plugs, and which is provided
near its upper end with a plurality of slots or perforations which
function to admit hydrocarbon to the interior of the skimmer tube.
Disposed concentrically within the skimmer tube so as to define an
annulus therewith is a cylindrical bladder housing or chamber. The
bladder housing extends from the top closure plate of the skimmer
tube to a location spaced upwardly from the bottom closure plate
thereof.
A flexible cylindrical bladder lines the inner wall of the housing
and is secured in this position by an upper and lower check valve
assembly inserted in the upper and the lower ends, respectively, of
the bladder housing. A tube or pipe is connected to the upper check
valve assembly for permitting a hydrocarbon liquid, or other
deleterious low density liquid material, to be expelled from the
interior of the bladder during operation of the pump. The lower
check valve assembly functions to admit hydrocarbon liquid to the
interior of the cylindrical bladder from the intake portion of the
pumping cycle.
At least one fluid flow tube projects through the upper closure
plate and communicates at its lower end with the space between the
cylindrical bladder housing and the exterior of the flexible
bladder. The fluid flow tube is externally connected to an
automatic timing and control means which functions to control the
time periods during the pumping cycle when air under pressure is
charged to the space between the bladder and its surrounding
bladder housing, and when this air is evacuated from this space,
and when the space is simply vented to the atmosphere so that the
pump is allowed to undergo a filling phase. During this phase, the
space defined within the cylindrical bladder fills with hydrocarbon
or other relatively light liquid from the subterranean location
where the pump is positioned.
An important object of the present invention is to provide an
improved pump which can be very effectively employed to separate
supernatant hydrocarbon liquids and/or other lighter-than-water
liquids floating on top of the water within a saturated water zone
in a subterranean location.
Another object of the invention is to provide a pump for pumping
environmentally deleterious liquids by the use of a gas employed to
operate the pump, and to carry out such pumping in a way such that
the pumping gas does not become contaminated with vapors from the
liquid which is pumped so as to constitute a potential atmospheric
pollution hazard.
Another object of the invention is to provide a bladder pump which
uses both a positive force to expel liquids from the pump by
constriction or contraction of the bladder, and also a positive
force to distend the bladder by vacuum, and thereby return it to
its original preconstricted geometric configuration.
A further object of the invention is to provide a bladder pump
which is suitable for downhole use in pumping liquids from a
subterranean location, and which has few moving parts within the
part of the pumping assembly located in the well bore, and which is
constructed so that such moving parts do not easily become damaged,
torn or worn out over extended periods of usage.
Additional objects and advantages will become apparent when the
following detailed description of the invention is read in
conjunction with the accompanying drawings which illustrate a
preferred embodiment of the invention.
GENERAL DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical sectional view through the bladder pump of the
invention as the pump appears when it is located in a downhole
position within a screen at the lower end of a casing preparatory
to use of the bladder pump for removing a lighter-than-water
contaminant from a subterranean location.
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is a partial side elevation view of the upper portion of the
bladder pump of the invention illustrating the manner in which a
slotted fluid intake screen of an outer skimmer tube is secured in
the pump assembly.
FIG. 4 is an enlarged sectional view of one of the check valve
assemblies used in the bladder pump.
FIG. 5 is a partially sectional, partially diagrammatic view
illustrating the pump at the end of a pumping stroke with the
bladder collapsed.
FIG. 6 is a schematic view of the bladder pump external pneumatic
control system which is used to set and control the pressure,
exhaust and vacuum phases of the operating cycle of the pump.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
The bladder pump 10 of the invention is illustrated in FIG. 1 as it
appears when disposed in an operating situs. The bladder pump 10 is
suspended in a well bore 12 lined by casing 14 which carries a
perforated well screen 16 at its lower end. The well casing 14
projects upwardly to a location above the surface 18 of the ground
as shown in FIG. 1.
The well bore 12 traverses a water saturated formation 19 in the
earth, and the purpose of projecting the well bore into the earth
at this location is to remove hydrocarbons or other
lighter-than-water contaminants which, due to density difference,
float on the upper surface of the water in the water saturated
formation. Such layer of contaminants is designated generally by
reference numeral 20 in FIG. 1 of the drawings.
A discharge pipe 22 connected to and extending upwardly from the
pump 10 is provided for discharging hydrocarbon liquid pumped from
the hydrocarbon layer in the subterranean formation in the manner
hereinafter described.
The bladder pump 10 is also connected by suitable tubing or
conduits to a pneumatic external control system. Thus, a pipe or
tubing 24 projects upwardly from the pump 10 to the surface and is
connected to a pump cycle external control system. The control
system is illustrated in detail in FIG. 6, and is hereinafter
described. A part of the external control system is pictured
diagrammatically in FIG. 1, and there denominated generally by
reference numeral 26. The schematic portrayal at 26 in FIG. 1 can
actually be equated to a high capacity three-way poppet valve,
hereinafter described, which three-way valve is used for delivering
a pressure fluid, such as pressurized air, to the pump 10 at one
phase of the pumping cycle. This three-way valve is also used for
exhausting a pressurized fluid from the pump 10 during another
phase of the pumping cycle, and finally, for applying a vacuum to a
bladder forming a part of the pump to expand the bladder during
another phase of the pumping cycle.
Liquids from the liquid saturated portion of the formation adjacent
the perforated well screen 16 flow through the perforations in the
screen and into an annulus 30 which surrounds the pump 10 as shown
in FIG. 1. Within the annulus 30 the liquids stratify so that the
heavier water layer 32 is lower within the annulus, and the
hydrocarbon liquid 34 floats on top of the water layer. The pump 10
is suspended by a wire line (not shown), or is positioned by any
other suitable means, within the well bore 12 so that a fluid
intake slotted upper end portion 36 of an external skimmer tube 38
forming a part of the pump 10 is located just above the interface
between the hydrocarbon layer and the water layer, and thus will
function to admit only hydrocarbon to the interior of the skimmer
tube 38. At its lower end, the skimmer tube 38 is closed by a
bottom skimmer tube closure plate 40, and at its upper end it is
closed by a top skimmer tube closure plate 42. The skimmer tube 38
is secured to the top skimmer tube plate 42 by a plurality of
suitable screws 44 as shown in FIG. 3.
Positioned concentrically within the skimmer tube 38 is a
cylindrical bladder support chamber designated generally by
reference numeral 46. The cylindrical bladder support chamber 46 is
constructed by joining a pair of semicylindrical chamber halves 48
and 50, with each of the semicylindrical chamber halves having a
pair of radially outwardly directed coplanar flanges as shown in
FIG. 2. Thus, the semicylindrical chamber half 50 carries radially
extending coplanar flanges 52 and 54, and the semicylindrical
chamber half 48 carries radially extending flanges 56 and 58. In
assembling and constructing the bladder support chamber 46, the
flanges are aligned, as shown in FIG. 2, and are secured to each
other by means of suitable screws or fastening devices 60 as shown
in FIG. 3.
The cylindrical bladder support chamber 46 is internally lined with
a flexible, resilient bladder 62 which is preferably constructed of
Viton coated, Kevlar fabric. VITON is a fluoroelastomeric
co-polymer of vinylidine fluoride and hexafluoropropylene, and
KEVLAR is an aromatic polyamide fiber. The bladder 62 is
substantially coextensive in length with the cylindrical bladder
support chamber 46. The bladder 62 is made of two semicylindrical,
flanged parts 63a and 63b each of which carry a pair of opposed
aligned diametric flanges which are trapped or wedged between the
flanges 52, 54, 56 and 58 as shown in FIG. 2. The outside diameter
of the bladder 62 in a relaxed condition corresponds substantially
to the inside diameter of the bladder support chamber.
The bladder 62 is retained in the illustrated position within the
cylindrical bladder support chamber 46 by means of a pair of check
valve assemblies 64 and 66. The check valve assemblies 64 and 66
are pressed tightly into the upper and lower ends, respectively, of
the cylindrical bladder support chamber so as to wedgingly and
frictionally engage the upper and lower ends of the bladder 62, and
trap the bladder and hold it in a fixed position within the bladder
support chamber 46. It is possible, and is indeed preferred, to
construct the check valve assemblies 64 and 66 substantially
identically so that they can be used interchangeably.
The upper check valve assembly 64 includes a check valve head 68
which includes a generally cylindrical portion 70 of approximately
the same outer diameter as the diameter of the flexible bladder 64,
and a frustoconical lower portion 72 adjacent the cylindrical upper
portion, which lower portion projects inwardly and downwardly
within the bladder 62. The check valve head 68 carries an external
circumferential or annular groove for the accommodation of an
O-ring seal 78.
The check valve head 68 defines a central, axially extending bore
80 which projects from one end to the other of the check valve
head, and terminates in an opening at the inner end of the
frustoconical portion 72. Adjacent the opening of the bore 80 in
the frustoconical end portion of the upper check valve 64, the bore
80 is threaded to permit a check valve seat 82 to be threaded into
the bore. The check valve seat 82 is provided with a seat surface
86 and a fluid passageway 88. It is also provided with transverse
ports 90 which allow fluid to enter the passageway.
Extending diametrically across the bore 80 through the check valve
head 68 is a ball check stop rod 94. The ball check stop rod 94
functions to limit the opening movement of a ball check 96 which is
adapted to move off of the seat surface 86 at a time when the upper
check valve assembly 64 is in an open status.
The upper end portion of the bore 80 through the upper check valve
head 68 ends in an upper opening at the upper end of the check
valve head. Adjacent this upper opening, the bore 80 is threaded as
shown at 100 to enable it to threadedly engage external threads
carried on the lower end of a tubing sub 101 which is pressed into
the lower end of the discharge pipe 22 hereinbefore described.
As previously indicated, the lower check valve assembly 66 is
constructed quite similarly to the upper check valve assembly 64,
and thus includes a lower check valve head 102 which includes a
lower, generally cylindrical portion 104 and an upper or internal
frustoconical portion 106. An external annular groove 108 is
carried on the generally cylindrical portion 104 to permit an
O-ring seal 110 to be located in the groove, and to seal against
the internal surface of the bladder 62 when the lower check valve
assembly 66 is pressed into the lower end of the cylindrical
bladder support chamber 46 with the bladder surrounding it.
The lower check valve assembly 66 also has an axially extending
bore 111 projecting from the lower to the upper side of the check
valve head, and defining, at the upper or inner end thereof, an
opening 112 which functions to receive an externally threaded fluid
passageway nipple 114. The fluid passageway nipple 114 preferably
has transverse openings 116 which communicate with a central
passageway 117 therethrough. The passageway 117 is axially aligned
and communicates with the bore 111 through the check valve head 102
of the lower check valve assembly 66.
A second check valve head 118 is threaded into the internally
threaded lower end portion of the bore 111 of the lower check valve
assembly 66, and defines a seating surface 120 at the upper end
thereof. The seating surface 120 functions in cooperation with a
ball check 122 to check fluid flow out of the cylindrical bladder
62 during one phase of the operation of the pump as hereinafter
described. The opening movement of the ball check 122 is limited by
a transversely extending ball check stop rod 124.
It will be noted in referring to FIG. 1 of the drawings that the
lower or outer check valve head 118 of the lower check valve
assembly 66 projects into the space defined between the lower end
of the cylindrical bladder support chamber 46 and the bottom
skimmer tube closure plate 40 which closes the lower end of the
cylindrical skimmer tube 38. From the description thus far, it will
now be perceived that liquid from the annulus 30 between the pump
10 and the well screen 16 can pass into the external skimmer tube
38 via the openings through the slotted fluid intake upper end
portion 36 of the skimmer tube. From this point of entry, the
hydrocarbon liquids gravitate downwardly into the space adjacent
the lower end of the cylindrical bladder support chamber 46 where
it is closed by the lower check valve assembly 66. From this
position, the liquid thus introduced into the external skimmer tube
38 is positioned to pass through the lower check valve assembly 66
into the interior of the cylindrical bladder 62 during an intake
phase of the operation of the pump as hereinafter described. It
will also be noted that any fluid which is located within the
bladder 62 can be discharged from this location through the upper
check valve assembly 64 and into the hydrocarbon liquid discharge
pipe 22 when the upper check valve 64 is in an open status. This
occurs during one phase of the operating cycle of the pump 10, and
will be hereinafter described.
For the purpose of permitting the flexible cylindrical bladder 62
to be operated so as to cyclically undergo a pumping movement, a
pair of fluid flow tubes 128 and 130 are projected through sealed
openings in the top skimmer tube closure plate 42. These tubes
extend downwardly through the annulus between the cylindrical
bladder support chamber 46 and the external skimmer tube 38 to a
location spaced upwardly a short distance from the bottom of the
cylindrical bladder support chamber 46. The fluid flow tubes 128
and 130 communicate, at their lower ends, through the cylindrical
bladder support chamber 46 with the outer side of the bladder 62.
They are thus able to function to deliver an actuating fluid to the
space between the bladder 62 and the cylindrical bladder support
chamber 46, or, at a different time during the pump operating
cycle, to evacuate this space, all in response to a pneumatic
external control system 26 hereinafter described.
The pump 10 is connected to the pneumatic external control system
26 through a three-way poppet valve 132 which forms a part of the
control system. The shifting of the three-way poppet valve 132
functions to sequentially connect it to various sources of pressure
fluid, or vacuum or atmospheric exhaust, at different phases of the
pumping cycle as hereinafter described. As shown in FIG. 6, the
three-way poppet valve 132 includes a fluid actuated pilot 134
which functions, at certain times during operation of the pump, to
cause shifting of this valve.
The control system 26 which includes the high capacity three-way
poppet valve 132 is illustrated in FIG. 6 of the drawings. A
pressurized gaseous fluid, such as air, used for operating the
bladder pump 10 is charged through the control system 26 shown in
this Figure. The pneumatic external control system 26 thus receives
high pressure air at a typical pressure of about 100 psi via a
charging conduit 138. The high pressure air enters the system
through a high capacity filter 140 and a high capacity pressure
regulator 142. Air discharged from the high capacity pressure
regulator 142 is divided and the main volume of the air from the
regulator flows through a relatively large diameter conduit 144. A
relatively smaller volume of air from the regulator 142 flows
through a smaller diameter conduit 146.
It will be perceived that the main volume of air flowing in the
conduit 144 is directed to the high capacity three-way poppet valve
132, and is shown, from the status of the latter valve, as being
directed through this valve into the pipe 24. The pressurized air
is therefore at this time being directed to the pump 10, and, as
will be subsequently explained, is functioning to force the
collapse of the bladder 62 inwardly toward the position shown in
FIG. 5. The described status of the three-way poppet valve 132
occurs at a time when the pilot 134 of this valve is not
pressurized.
The relatively small volume of pressurized air from the conduit 146
flows through a low volume filter 148 and a low volume pressure
regulator 150. The low volume pressure regulator 150 is, in a
preferred method of operation, adjusted to a pressure of about 50
psi as shown on the pressure gauge 151.
After passing through the low volume pressure regulator 150, the
air discharged therefrom flows through a conduit 152 to a three-way
valve 154, hereinafter referred to as the exhaust cycle valve. In
the illustrated status of the exhaust cycle valve 154, air passes
through this valve into a conduit 156 by which the air is conducted
to the flow control and check valve assembly 158 which controls the
flow of air to the pilot 160 of a three-way valve 162 hereinafter
referred to as the pressure cycle valve.
At this time, high pressure air of a relatively large volume
continues to flow to the pump 10 through the three-way valve 132
for a period of time which is determined by the size of an air
volume chamber 164 and the setting of an adjustable flow control
166, both of which form parts of the flow control and check valve
assembly 158 associated with the pilot 160 of the three-way
pressure cycle valve 162. The described parameters, in conjunction
with the pilot acutation pressure which is characteristic of the
pilot 160, will determine the time period over which the pressure
cycle continues and high pressure air continues to be delivered to
the pump 10 via the pipe 24 and the fluid flow tubes 128 and
130.
It will be perceived that during this part of the cycle, high
pressure air is delivered to the space between the bladder 62 and
the cylindrical bladder support chamber 46 so as to force
constriction of the cylindrical bladder radially inwardly in the
manner illustrated in FIG. 5. This will cause fluid contained
within the bladder 62 to be expressed or discharged from that
space, and this forces the opening of the upper check valve
assembly 64, and the closure of the lower check valve assembly 66.
In a preferred method of operating the pump 10 of the invention,
the pressure cycle of the pump is set to extend over a period of
from zero to thirty seconds by adjustment of the pilot acutation
pressure of the pilot 160, the size of the volume chamber 164 and
the flow allowed through the adjustable control valve 166.
When an adequate pressure has built up in the volume chamber 164,
the result is that the pilot 160 will respond to this pressure and
will shift the three-way pressure cycle valve 162. The shifting of
the three-way pressure cycle valve 162 causes air under pressure to
be directed from a conduit 172 through the valve 162 and into a
conduit 174. The pressurized air in the conduit 174 is applied to
the pilot 134 of the three-way poppet valve 132. The pressurized
air from the conduit 174 also is directed through a branch conduit
178 to a timing control assembly 180 of the three-way exhaust cycle
valve 154. The timing control assembly 180 includes a volume
chamber 182 and an adjustable flow control valve 184. The timing
control assembly 180 functions to control the air pressure which is
applied to the pilot 186 of the three-way exhaust cycle valve
154.
Concurrently with the application of pressure through the conduit
178 to the timing control assembly 180, air under pressure is
applied through the conduit 190 to a timing control assembly 192
associated with a three-way vacuum cycle valve 194 and its
associated pilot 196. The timing control assembly 192 includes a
volume chamber 198 and an adjustable flow control valve 200.
The pressure applied to the pilot 134 of the three-way poppet valve
132 at this time shifts this valve so as to connect the pump 10
through the valve 132 to a conduit 202. The conduit 202 is
connected to a high capacity four-way valve 204 which is operated
by a pilot 206 acting in opposition to a spring 208. At this time,
the three-way vacuum cycle valve 194 is shifted so that pressurized
air from a conduit 210 passes through the vacuum cycle valve and
enters a conduit 212 which acts upon the pilot 206 of the four-way
valve 204.
When the pilot 206 responds to pressure from the conduit 212 to
shift the valve 204, the result is that relatively high pressure
air from the conduit 144 passes through the valve 204 and is
discharged through a Venturi ejector 214. Flow of high pressure air
through the Venturi ejector 214 causes a vacuum to be generated
which acts through the then connecting port through the valve body
of the four-way valve 204 to apply a vacuum to the conduit 202.
This vacuum is thus applied at this time to the pump 10 by way of
the three-way poppet valve 132 which has been shifted as previously
described.
The vacuum thus developed is applied to the pump 10 through the
fluid flow tubes 128 and 130 so that the air between the bladder 62
and the cylindrical bladder support chamber 46 is evacuated, and
the bladder 16 is drawn outwardly against the internal wall of the
bladder support chamber. The vacuum developed at the Venturi
ejector 214 is applied to the pump 10 for a period of time which is
determined by the size of the volume chamber 198 of the three-way
vacuum cycle valve 194, as well as the adjusted flow rate through
the adjustable flow control valve 200, and the minimum pilot
actuation pressure which has been made to characterize the pilot
196 of the three-way exhaust cycle valve 194. These component
characteristics should be selected so as to achieve a timing period
for the application of vacuum to the pump over a period of from
zero to fifteen seconds.
It will be recalled that at the time adequate pressure has been
built up to shift the three-way pressure valve 162, thereafter
pressure is applied to the pilot of the three-way exhaust cycle
valve 154, and also to the pilot 196 of the three-way vacuum cycle
valve 194. Thus, both timing periods for the exhaust cycle and the
vacuum cycle begin at the same time. The vacuum cycle flow
adjustment control valve 200 is set, however, to a time period
which is approximately ten seconds, whereas the exhaust cycle flow
adjustment control valve 184 is set for a time which is typically
substantially greater than ten seconds. Therefore, the vacuum cycle
during the operation of the pump will end before the exhaust cycle
valve is shifted by its pilot.
When adequate pressure is built up in the volume chamber 198
associated with the three-way vacuum cycle valve 194, this vacuum
cycle valve shifts. This causes pressure to be applied to the pilot
206 of the four-way valve 204, causing the four-way valve to
exhaust fluid from the pump to the atmosphere, and shifting the
four-way valve to remove the Venturi ejector 214 from its
connection to the vacuum and pressurized air supply lines. This is
the status of the four-way valve 204 as it is illustrated in FIG.
6.
The pump 10 is allowed to exhaust to the atmosphere, A, through the
valve 132, conduit 202 and valve 204 for a period of time which is
determined by the size of the volume chamber 182, the flow through
the adjustable metering or flow valve 184 and the minimum pilot
actuation pressure of the pilot 186 associated with the three-way
exhaust cycle valve 154. The exhaust cycle should be set to operate
over a period of up to about six hours to give adequate time for
the bladder 62 to fill. Under normal operations, during the
beginning of pumping underground hydrocarbon contaminants, the
initial hydrocarbon stratum thickness will be relatively great, and
initial hydrocarbon fluid production will occur in high volume and
at a relatively rapid rate, and the bladder fill time is then set
to zero or a very low time delay. After one or two years of
continuous recovery of hydrocarbon contaminants, however, the fluid
production will decrease greatly, and there will be a very thin
layer of hydrocarbons remaining on the water. The well may then
take several hours to accumulate enough fluid in the fill tube to
fill the pump cavity. At this time, setting the system for a fill
time of as much as six hours may often be desirable.
At the end of the described period, when adequate pressure is built
up in the volume chamber 182, the pilot 186 then shifts the
three-way exhaust cycle valve 154. The valve 154 shifts from the
position illustrated in the drawing to a position such that
pressure is relieved from the pilot 160 on the three-way pressure
cycle valve 162 through the check valve connected in parallel with
the flow control valve 166. This air thus relieved from the pilot
160 can thus be exhausted to the atmosphere through the shifted
three-way exhaust cycle valve 154. This pressure release from the
pilot 160 on the three-way pressure cycle valve 162 allows this
valve to return to the position illustrated in FIG. 6. Pressurized
air in the conduit 174 is then vented to the atmosphere and this,
in turn, relieves the pressure on the pilots 186, 134 and 196 of
the valves 154, 132 and 194, respectively. The shifting of these
valves in this fashion by relief of the pressure applied to their
pilots brings the control system back to the original starting
state, and the process then repeats as long as the air supply
pressure is maintained.
OPERATION
In operating the bladder pump 10 of the invention, the pump is
connected to the pneumatic external pump cycle control system 26
through the three-way poppet valve 132. As illustrated in FIG. 1,
this poppet valve can be schematically portrayed, at different
times in the operating cycle, as exhausting air from the pump to
the atmosphere, evacuating air by the development of vacuum to draw
the air from the space between the flexible bladder 62 and the
bladder support chamber 46 and pressurizing the pump by the
delivery of air under pressure to the space between the flexible
bladder and the bladder support chamber.
After the pump 10 has been positioned in the well bore 12 in the
location shown relative to the interface between the lighter
hydrocarbon liquid and the underlying water, the first phase in the
operation of the pump is a filling phase. Hydrocarbon liquid is
allowed to flow through the slots or openings in the slotted fluid
intake upper end portion 36 of the external skimmer tube 38. The
hydrocarbon liquid then gravitates downwardly in the annulus 30
between the skimmer tube 38 and the outer surface of the
cylindrical bladder support chambers 46.
From the space in the closed lower end of the skimmer tube 38, the
hydrocarbon can, during the exhaust cycle of the pump, flow
upwardly through the lower check valve assembly 66 into the
interior of the pump, slowly filling that space defined within the
bladder 62. At this time, the hydrostatic head of the hydrocarbon
is entirely adequate to cause the ball check 122 to be unseated to
allow the hydrocarbon to move upwardly through the lower check
valve assembly into this space within the bladder 62. The timing of
the exhaust cycle has been set to allow adequate time for
substantially the entire space within the bladder 62 to become
filled with hydrocarbon.
At the end of the exhaust cycle, the pressure cycle commences, and
at this time, the three-way poppet valve 132 is shifted to a
position such that pressurized air in the conduit 144 is directed
into the pipe 24 and from the pipe 24 into the fluid flow tubes 128
and 130. The fluid flow tubes 128 and 130 introduce the pressurized
air into the lower end of the space between the bladder 62 and the
cylindrical bladder support chamber 46. This causes the bladder to
be collapsed inwardly to the dashed line position shown in FIG. 1.
Inward movement of the bladder 62 in this fashion expresses, or
forces the discharge of, the hydrocarbon liquid contained in the
interior of the bladder. The hydrocarbon liquid, as thus placed
under pressure by the collapse or constriction of the bladder 62,
forces the ball check 96 of the upper check valve assembly 64 to
unseat and this check valve assembly opens. The hydrocarbon liquid
can thus be discharged through the discharge pipe 22 which is
connected to the short tubing section 101 which projects through
the center of the top skimmer tube plate 42.
After the pressure cycle has been maintained for the present
duration, the bladder is totally collapsed or constricted, as shown
in FIG. 5 of the drawings. At this time, all of the hydrocarbon
liquid will have been discharged from the space within the bladder.
In the next cycle of the pump, a vacuum is applied to the bladder
62 to cause it to move outwardly from its collapsed position and to
resume its original position in which it lies smoothly along, and
in registry with, the internal wall of the cylindrical bladder
support chamber 46. This is an important characteristic and feature
of the present invention. Application of the vacuum assures that
the bladder will be distended to its fully open position in a
uniform manner. Any tendency of the sides of the collapsed bladder
to stick to each other is overcome. The uniform and timely return
of the bladder to its position for receiving the hydrocarbon liquid
to be pumped assures that the service life of the bladder will be
greatly extended, and that discontinuities or stress points which
are likely to cause a rupture or failure of the bladder at certain
points therealong are minimized. In general, the overall service
and effective operating life of the bladder pump is greatly
extended.
Although certain preferred embodiments of the invention have been
herein described, it will be understood that various changes and
innovations of the invention can be effected without departure from
the basic operating principles which have been described. For
example, the bladder 62 can be constructed as a single cylindrical
unit, although this is a less preferred form of the invention.
Changes of this type are deemed to be circumscribed by the spirit
and scope of the invention, except as the same may be necessarily
limited by the appended claims or reasonable equivalents
thereof.
* * * * *